If you take foodstuff from impious men, then that means you are taking share of his impious activities

Expressions researched:
"Food prepared by an unclean, sinful man or woman, especially a prostitute, is extremely infectious" |"If we take food from the houses of others, such as karmis, we shall have to share the qualities of those from whom we take alms" |"If you take foodstuff from impious men, then that means you are taking share of his impious activities" |"if there is no Deity worship, if we take food from their house, then we partake the sin, resultant action of their sinful activities"

SB Canto 6

Food prepared by an unclean, sinful man or woman, especially a prostitute, is extremely infectious.

SB 6.1.67, Translation and Purport:

This brāhmaṇa irresponsibly spent his long lifetime transgressing all the rules and regulations of the holy scripture, living extravagantly and eating food prepared by a prostitute. Therefore he is full of sins. He is unclean and is addicted to forbidden activities.

Food prepared by an unclean, sinful man or woman, especially a prostitute, is extremely infectious. Ajāmila ate such food, and therefore he was subject to be punished by Yamarāja.

CC Antya-lila

If we take food from the houses of others, such as karmīs, we shall have to share the qualities of those from whom we take alms. Therefore Śrī Caitanya Mahāprabhu took prasādam in the houses of Vaiṣṇavas. This is the general process.

CC Antya 3.101, Purport:

In the days of Haridāsa Ṭhākura, all the brāhmaṇas worshiped Nārāyaṇa in the form of the śālagrāma-śilā. Therefore begging from a brāhmaṇa's house meant taking kṛṣṇa-prasādam, which is transcendental (nirguṇa). If we take food from the houses of others, such as karmīs, we shall have to share the qualities of those from whom we take alms. Therefore Śrī Caitanya Mahāprabhu took prasādam in the houses of Vaiṣṇavas. This is the general process. The members of the Kṛṣṇa consciousness movement are advised not to take food from anywhere but a Vaiṣṇava's or brāhmaṇa's house where Deity worship is performed. Śrī Caitanya Mahāprabhu has said, viṣayīra anna khāile duṣṭa haya mana: (CC Antya 6.278) if a devotee takes alms or food from the house of a karmī who is simply interested in money, his mind will become unclean. We must always remember that a devotee's life is one of vairāgya-vidyā, or renunciation and knowledge. Therefore all devotees are warned not to live unnecessarily luxurious lives at the cost of others. Gṛhasthas living within the jurisdiction of the temple must be especially careful not to imitate karmīs by acquiring opulent clothing, food and conveyances. As far as possible, these should be avoided. A member of the temple, whether gṛhastha, brahmacārī or sannyāsī, must practice a life of renunciation, following in the footsteps of Haridāsa Ṭhākura and the six Gosvāmīs. Otherwise, because māyā is very strong, at any time one may become a victim of māyā and fall down from spiritual life.

Srimad-Bhagavatam Lectures

If you take foodstuff from impious men, then that means you are taking share of his impious activities. A saintly person, he can digest, but if he cannot digest, then he has to suffer. This is the process. Then he has to suffer. Therefore the safety principle is to accept luncheon in a pious family, where there is Vaiṣṇava family or brāhmaṇa family.

Lecture on SB 5.5.1-2 -- Stockholm, September 7, 1973:

Still this custom is prevalent in India, as soon as somebody sees a sannyāsī has come in a temple, somebody from the village, not somebody, but many will come, "Sir, you can take your lunch at my place." So there is no scarcity. Many people will come to invite you still. Therefore many pseudo or phony swamis, they have taken this profession because there is no difficulty getting food. So, mahat-sevā. The... What is the idea? The idea is the gṛhasthas, they know that "We are simply engaged in the matter of sense gratification. If we invite some saintly person at home, if he eats at my place, then, we commit so many sinful activities, we'll be saved." This is the process. Therefore, a sannyāsī is advised to accept prasādam in the house of a brāhmaṇa, because a brāhmaṇa is supposed to be, become very pious. If you take foodstuff from impious men, then that means you are taking share of his impious activities. But a saintly person, they can digest, but if (they) cannot digest, then you have to suffer. This is the process. Then he has to suffer. Therefore the safety principle is to accept luncheon in a pious family, where there is Vaiṣṇava family or brāhmaṇa family. Not that anywhere we can accept cooked food. Sometimes we have to do it, but that is against principle. We should not accept food anywhere and everywhere, unless he is pious. The brāhmaṇas are supposed to be pious; therefore, a sannyāsī is advised to accept food, luncheon in the brāhmaṇa family. And brāhmaṇa family, still, not all, a few families still in India, they worship regularly Nārāyaṇa-śilā, śalagrāma-śilā.

Initiation Lectures

If there is no Deity worship, if we take food from their house, then we partake the sin, resultant action of their sinful activities. We should be careful. Unless it is prasādam, if we accept invitation from anywhere and everywhere, that means we are accepting the sinful activities, resultant action of the sin, person.

Sannyasa Initiation Lecture -- Calcutta, January 26, 1973:

Kilbiṣaiḥ means sinful activities. Therefore prasāda distribution. Because everyone is engaged simply duṣkṛtinaḥ, simply sinful activities. Eating everything, doing everything, and they're life is full of sinful activities. Therefore to deliver them this prasāda distribution is required. Mucyante sarva-kilbiṣaiḥ. Not that cooking in an, like a hotel, and sometimes, out of compassion, we distribute prasādam. That kind of, means bhuñjate te aghaṁ pāpā ye pacanty ātma-kāraṇāt (BG 3.13). Simply for feeding myself or yourself. Just like in marriage ceremony and other ceremonies we do. That, that bhuñjate te aghaṁ pāpā, they're simply eating pāpā. Therefore we are prohibited to take prasādam anywhere and everywhere. Because if there is no Deity worship, if we take food from their house, then we partake the sin, resultant action of their sinful activities. We should be careful. Unless it is prasādam, if we accept invitation from anywhere and everywhere, that means we are accepting the sinful activities, resultant action of the sin, person. Therefore a sannyāsī... And it was, formerly, this was the regulation, that sannyāsī would take prasādam in the house of a brāhmaṇa, because a brāhmaṇa is supposed to worshiper of Nārāyaṇa. In every house of a brāhmaṇa there was Nārāyaṇa-śilā. Still some rigid brāhmaṇas, they worship. So Caitanya Mahāprabhu even, He did not accept prasādam from a non-Vaiṣṇava brāhmaṇa. He must be brāhmaṇa, at the same time, Vaiṣṇava. Then He would accept.

So this regulation we should follow. We should not accept food, (only) prasādam. If anyone wants to give us food, then he must arrange for cooking food and offering to the Nārāyaṇa, to the Viṣṇu, Kṛṣṇa. Then we can take. This is the... Otherwise we... Bhuñjate te aghaṁ pāpā ye pacanty ātmā... People who are cooking for eating oneself, that cooking, that eating is simply sinful. Without prasādam, whatever we eat, that is, we are eating sin, That's all. Therefore we must suffer. We should be careful. Bhuñjate te aghaṁ pāpā. This is parātma-niṣṭhā, that we should not accept anything which is not offered to Viṣṇu, or Kṛṣṇa.